1. Field of the Invention
Embodiments of the present invention generally relate to methods and apparatus for separating particulates from a particulate-fluid mixture. More particularly, embodiments of the present invention relate to methods and apparatus for separating catalyst particulates from a reactor effluent.
2. Description of the Related Art
One approach to separating particulates from a particulate-fluid mixture utilizes a cyclone separator (or simply, “cyclone”). Introduction of the particulate-fluid mixture to the cyclone separator induces centripetal acceleration to the mixture, thereby forcing the higher density particulates outward toward the walls of the cyclone separator to provide a gas in the middle of the cyclone having reduced particulate content and the separated particulates along the separator walls. Fluid catalytic cracking (“FCC”) is a process that frequently uses cyclone separators to separate catalyst particulates from a product effluent containing gas and catalyst particulates entrained therein.
Current cyclone separator designs require a refractory lining on the inner surface of the cyclone separator. Without the refractory lining, catalyst particulates impinging on the surface of the cyclone erode the walls of the cyclone, which causes premature failure. However, current refractory linings often prematurely fail, especially at high temperatures, due to various factors, which include the growth of coke between the refractory lining and the cyclone's walls, within cracks or other imperfections of the refractory lining's surface, and/or between adjoining pieces or sheets of refractory material. After a sufficient amount of coke has formed, the refractory lining will break, chip, crack, and eventually portions or all of the refractory lining can completely detach from the cyclone walls rendering operation of the cyclone impossible.
There is a need, therefore, for more reliable methods and apparatus for separating particulates from a particulate-fluid mixture.